Tensioning device for wires, cables and the like



P. GOTTI March 27, 1934 TENSIONING DEVICE FOR WIRES, CABLES, AND THE LIKE Filed July 8," 1930 2 Sheets-Sheet l March 27, 1934. 1,952,668

TENSIONING DEVICE FOR WIRES, CABLES, ND THE LIKE P. GOTTI 2 Sheets-Sheet 2 Filed July 8, 1930 Patented Mar. 27, 1934 TENSEQNING DEVICE FGE WEB/ES, AND THE LIKE Pietro Gotti, Genoa, Italy Application July 8, 1930, Serial No. 466,605

in Germany July 9, i929 2 Claims.

This invention relates to tensioning devices for wires, cables or the like and comprises an improved device wherein a longitudinal support carries a relatively movable an" a relatively stationary member, each supporting a pair of clamps so arranged that upon the movable member being displaced in one direction the clamps thereon grip and move the wire to be tensioned, whilst that on thestationary member frees it, whereas upon the movable member being displaced in the opposite direction, the clamp thereon frees the wire which is thereupon. gripped by the clamp on the stationary member.

The main object of the invention is to provide a device of the above character wherein any excessive pressure or squeezing of the wire to be tensioned is avoided, by the operation of the device, by providing on the movable member very extensive cylindrical gripping surfaces, and by 0 mounting the gripping members, both on the movable and on the stationary block, freely movable upon the blocks, so that their gripping force will be always proportional to the tension of the wire. and not to the force as applied to the operating levers, which is aways transmitted to the movable block as a whole, the gripping action on the wire resulting from a frictional action of the ten sioned wire tending to slide from between the clamps and causing the clamps to approachto one '30 another.

Aiurther object of the invention is to provide means permitting the adjustment of the smallest distance between the clamping surfaces.

With the above and the other objects in view,

' as will be apparent from the following specification and pointed out in the appended claims the invention consists in the improved constructions and combinations of parts.

In the accompanying drawing:

Figures 1, 2 and 3 are respectively a top plan,

a side elevation and an end view of a first embodiment of the device, with parts broken away or shown in section;

Figure 4 is a top view, also partially in section, of a second embodiment of the invention,

cating motion can be imparted with respect to the fixed block 6 by the operation of a pair oi levers 9', 9' preferably arranged on the same side of the device in order to permit the operation by a single person and conne ted by means oi links 10, 10 to lugs 11, ii ured on block 6, the levers 9, 9 being intheir turn jointly connected at 12 to a bracket 13 which is an integral extension of block 8.

The clamps in their. simplest form consist of two pairs or wedged shaped jaws i l-14 and let-14, of rectangular trapezoid formation, slidable in suitable trapezoid cavities l5, 15 with in the blocks 8 and 6, respectively. The bottoms of these cavities are suitably slotted as at 16, to permit all rubbish and foreign matter deposited within the cavities to be easily removed. The clamps 14, 14' are connected in pairs by transverse sliding keys 1'? and are pushed towards the minor base of the trapezoidal cavities by springs 18 fitted within blind tubes 19 slidably fitted within axial bores of members or housings 26,28 integral with the blocks 6 and 8. respectively. damping jaws (14, 14) are maintained in their respective cavities 15, 15 by cover plates 21, held in place by screws. The roughened inner faces of said clamping jaws, owing to the inclination of the walls of cavities 15, 15' and of tubular guide housings or members 19. 20 and to the slidable key connection of the clamp pairs, are caused to slide 3 always parallel to one another thus firmly gripping any elongated body (wire, etc.) therebetween. The sectional shape of the gripping surfaces is further preferably curved for best and most extensive grip and minimum deformation of the wires or cables.

For best guiding of cables or thicker wires, grooved pulleys or rollers 3, 3" are provided at the ends of the path of the wire within the device, said grooved rollers being pivoted on slidable pins 4. In order to allow the clamping jaws to slide apart from one another, when inserting or taking out the wire, a transversal triangular block 22 is provided that bears against a correspondingly inclined surface on blocks l4, l4 and, when operated inwardly of cavity 15 or 15 by lever and links 23, 23' pushes clamps 14, 14 against the spring pressure and apart from one another.

Figures 5, 6 and 7 show a more suitable construction of wire tightener for use on thinner wires or also to wires for which no excessive straining is required.

In this instance a single tubular support 1 is suincient and the clampsare of the pivoted type, though provision has been made to provide for a most extensive gripping area, parallel of the wires to be grasped, and this especially for the straightener clamps, or clamps attached to the slidable block.

Further, in order to avoid that the minimum possible distance of the straightener clamps is too small for the wires to be tensioned, with a consequent danger of squeezing or deformation of these latter, the clamping members on the slidable block are preferably arranged as shown on the left side of Figure 4 and Figures 5 and 6. To this end the slotted arms 24 are slidably mounted upon a journalled guide block 25 and are longitudinally, adjustable upon this guide block by means of screw 26, which is rotatable but not axially shiftable on arm 24 owing to a connection by pin 27 and annular groove 28. In this manner by operating on screws 26, the arms 24 may be caused to slide towards or apart one another, for an amount as permitted by the slot in the arms 24. To the end of these arms 24 the clamping jaws or shoes 29 are pivoted on pin 30 integral of arm 24. Arms 24 are operatively connected by toothed segments 31 arranged below the arms 24 and shoes 29 and integral of journalled block 25. Radial slots 32 are out in the said segments for sliding connection with the projections of pins 30. The pivoted arms 24 are pushed towards one another by springs 33 and guide members 34. Also in this case, the gripping surfaces fit perfectly lengthwise along the wire sides, 1. e. parallel and not at any angle to the gripped wire section, thus avoiding any squeezing due to restricted clamping area. The holding clamps 35 on the fixed block 6 (Figures 4 and '7) are preferably of the shape as shown in Figure 4 and are pivoted on a transverse bar or slide 36 slidable within a cavity 3'7 of the fixed block, guided by a pair of side rails 38 and pushed inwardly by a spring 39 bearing with its opposite end against the fixed block 6. A hooked stem 40 is fitted to slide 36 for pulling same when desired to insert or to free the wire, the pulling of the member 36 against the tension of spring 39 acting to bring slide 36 and clamps 35 from the dotted line to the full line position. It is to be noted that the coming together of the clamps in their operating position is determined by the inclined walls 41, while the spreading apart is controlled by the wedge-like central projection 42 of block 6.

It will be understood that the above embodiments of the device are only given by way of example, and many combinations will be possible, that are not described for the sake of brevity, but that may be readily derived from the examples as shown.

Having thus described my invention, I claim:

1. A wire tensioning device comprising in combination a supporting bar, a fixed block at one end of said bar, hooks attached to this block, a second block slidable along the opposite end of the supporting bar, trapezoidal cavities within the fixed and the slidable block; cover plates closing said cavities, a pair of rectangular trapezoidal clamping jaws having roughened clamping sur faces and freely slidable within said cavities, connecting means between the jaws of each pair for parallel sliding thereof, springs acting on said jaws and comprising a pair of inclined longitudinal housings for the individual helical springs pressing each clamping jaw in one direction; blind guide tubes within said housings and helical springs within these tubes and pressing the trapezoidal jaws toward the smaller base of the trapezoidal cavities; and operating means acting upon a wedge-shaped shoe slidably fitted within the cavities opposite the minor base of the trapezoidal jaws and co-acting with suitable surfaces adjacent the minor base of the trapezoidal jaws in front of the hand-operated releasing wedge to spread the jaws apart when the hand-operated means are driven in one direction.

2. A wire tensioning device comprising in combination a supporting bar, a fixed block towards one end of the said bar, hooks attached to this block, a second block slidable along the opposite end of the supporting bar, cover plate closed cavities within the fixed and the slidable block, a pair of trapezoidal clamping jaws having roughened clamping surfaces and jointly slidable within the said cavities, means for causing these clamping jaws to come together when sliding in one direction in the said cavities; spring means acting to urge the said jaws in the said direction; and hand-operated means acting upon a wedge shaped shoe slidably fitted within the cavities opposite the minor base of the trapezoidal jaws and co-acting with suitable surfaces adjacent the minor base of the trapezoidal jaws in front of the said wedge to spread the jaws apart when the hand-operated means are operated in one direction.

PIETRO GOTTI. 

